The present invention starts from the need to coat tools, and thereby particularly cutting tools or form tools with a base body of metal, thereby in particular of HSS or of tool steel or of hard metal, in such a manner, that they are particularly suitable for dry processing operation or for operation under minimum lubrication (shortage lubrication) etc.
From the solution of this problem and according to the present invention there results a protection coating technique, which is suitable also for other tools and mechanical components, when they are used with little or no lubrication and/or under a high surface loading.
Under ecological and under economical considerations, the operation of tools, in particular of cutting tools and of form tools under minimum lubrication conditions is highly interesting. Under economical aspects it has to be noted that the costs for cooling lubricant, in particular for cutting tools, are substantially higher than for the tool itself. By applying cooling lubricant in the contacting area of tool and workpiece, chips are washed out and heat is dissipated, furthermore a cleaning and corrosion-preventing effect is reached.
There exists an increasing and substantial need to stop using conventional amounts of cooling lubricant, e.g. of 300 to 4000 liters per hour, for a chipping tool processing, and to drastically reduce that amount to, e.g., only 6 to 70 ml per hour for the same number of operations.
This leads to a highly sophisticated task, on the one hand, with respect to forming of the tools, on the other hand, with respect to surface treatment applied to such tools and mechanical components. The present invention addresses the last mentioned task.
In the context of the aforementioned problem the task mentioned above is resolved by proposing a tool or mechanical component at which, according to the invention, the hard material coating system comprises at least one hard material layer made of a material selected from the group of Nitrides, Carbides, Oxides, Carbonitrides, Oxynitrides or also herein Oxinitrides, Oxycarbonitrides or also herein Oxicarbonitrides of at least one metal, and further an intermediate layer is provided immediately between the mentioned at least one hard material layer andxe2x80x94propagating in direction from the inside of the base body towards its outsidexe2x80x94before the slide layer system, which intermediate layer is made of the same at least one metal, which is present in the at least one hard material layer of the hard material layer system.
It is known from the U.S. Pat. No. 5,707,748 of the same applicant as the present application to deposit a hard material layer system onto the base body of a tool, directly followed by a slide protection layer system. As materials for the hard material layer system metal Carbides, metal Nitrides, metal Carbonitrides or combinations thereof have been proposed, as materials for the slide protection layer system materials based on Carbon, such as especially Tungsten carbide or also herein Tungstencarbide with dispersed Carbon, WC/C. The known coating has been used with the principal target of increasing the etch life of cutting tools.
The present invention starts from the finding that this known coating technique can be used to fulfil the extreme requirements underlying the problem to be solved in respect to the tools or mechanical components, in particular to cutting tools, if the known overall layer system is construed as proposed by the present invention, in particular by means of inventively providing the metallic intermediate layer.